“I don’t remember having a problem this unique in previous cycles — where you have incumbent so ripe for the taking and, at this point, no candidates able to get the job done, one Republican source told the Examiner.

But Campbell spokesman Mike Schrimpf dismissed concerns about Campbell’s viability in a statement to the newspaper.

“It’s no surprise that many of the same D.C. insiders who never thought President Trump could win are pitching opposition research against Tom Campbell, who has pledged to be a strong ally of President Trump,” he said. “The truth is many of these issues have already been reported on in North Dakota and voters there can see right through them.”

A GOP operative said among the concerns about Campbell is that his bank foreclosed on North Dakota farmers, and he was sued for fraud over a life insurance policy on his mother.

There is also concern that he co-sponsored a bill easing regulation on hemp production and has said he intends to grow hemp on his farm.

“Campbell's bank has foreclosed on a number of ND farmers. All Democrats need to do is put one on camera and he’s toast,” the operative said. “And that’s before they tell everyone how he lied on a life insurance application to get rich off of his own mother’s death.”

Trump won North Dakota by 36 points, but Heitkamp is still considered a strong incumbent, having won the state in 2012 when Barack Obama lost it.